Molecular co-assembled strategy tuning protein conformation for cartilage regeneration

The assembly of oligopeptide and polypeptide molecules can reconstruct various ordered advanced structures through intermolecular interactions to achieve protein-like biofunction. Here, we develop a “molecular velcro”-inspired peptide and gelatin co-assembly strategy, in which amphiphilic supramolecular tripeptides are attached to the molecular chain of gelatin methacryloyl via intra-/intermolecular interactions. We perform molecular docking and dynamics simulations to demonstrate the feasibility of this strategy and reveal the advanced structural transition of the co-assembled hydrogel, which brings more ordered β-sheet content and 10-fold or more compressive strength improvement. We conduct transcriptome analysis to reveal the role of co-assembled hydrogel in promoting cell proliferation and chondrogenic differentiation. Subcutaneous implantation evaluation confirms considerably reduced inflammatory responses and immunogenicity in comparison with type I collagen. We demonstrate that bone mesenchymal stem cells-laden co-assembled hydrogel can be stably fixed in rabbit knee joint defects by photocuring, which significantly facilitates hyaline cartilage regeneration after three months. This co-assembly strategy provides an approach for developing cartilage regenerative biomaterials.

For all statistical analyses, confirm that the following items are present in in the figure legend, table legend, main text, or or Methods section.

n/a Confirmed
The exact sample size (n) for each experimental group/condition, given as as a discrete number and unit of of measurement A statement on on whether measurements were taken from distinct samples or or whether the same sample was measured repeatedly The statistical test(s) used AND whether they are one-or or two-sided Only common tests should be described solely by name; describe more complex techniques in the Methods section.

A description of of all covariates tested
A description of of any assumptions or or corrections, such as as tests of of normality and adjustment for multiple comparisons A full description of of the statistical parameters including central tendency (e.g.means) or or other basic estimates (e.g.regression coefficient) AND variation (e.g. standard deviation) or or associated estimates of of uncertainty (e.g.confidence intervals) For null hypothesis testing, the test statistic (e.g.F, t, r) with confidence intervals, effect sizes, degrees of of freedom and P value noted Give P values as exact values whenever suitable.
For Bayesian analysis, information on on the choice of of priors and Markov chain Monte Carlo settings For hierarchical and complex designs, identification of of the appropriate level for tests and full reporting of of outcomes Estimates of of effect sizes (e.g.Cohen's d, Pearson's r), ), indicating how they were calculated Our web collection on statistics for biologists contains articles on many of the points above.

Data analysis
For manuscripts utilizing custom algorithms or or software that are central to to the research but not yet described in in published literature, software must be be made available to to editors and reviewers.We We strongly encourage code deposition in in a community repository (e.g.GitHub).See the Nature Portfolio guidelines for submitting code & software for further information.We require information from authors about some types of materials, experimental systems and methods used in many studies.Here, indicate whether each material, system or method listed is relevant to your study.If you are not sure if a list item applies to your research, read the appropriate section before selecting a response.Note that full information on on the approval of of the study protocol must also be be provided in in the manuscript.

Novel plant genotypes
Seed stocks

Plants
The literatures about the relation between estrogen and chondrocyte regeneration have shown that estrogen could decrease cartilage thickness by by inhibition of of chondrocyte proliferation and increased chondrocyte maturation (Talwar RM RM et et al., J Oral Maxillofac Surg. 2006;64(4):600-609).Therefore, in in order to to avoid the influence of of estrogen on on the evaluation of of cartilage regeneration, we we only choose male rabbits as as experiment animals in in this study.
No No field collected samples were used in in the study.
All studies of of in in vivo inflammatory response test, ectopic chondrogenesis and cartilage regeneration were approved by by the permission of of the Sichuan University Ethics Committee (protocol number KS2020330) and were carried out according to to the institutional guidelines.